Page:Transactions NZ Institute Volume 15.djvu/500
It has been collected from Red Hill, Collingwood, by Dr. Hector (Col. Mus. & Lab. Rep., xiii., p. 35).
Bronzite, Ṁg (Ḟe) S̈i.—The occurrence of this mineral in diorite rocks of the West Coast is mentioned by Dr. Hector (Jurors' Rep. N.Z. Ex., 1865, pp. 266, 438), and by Mr. E. H. Davis at the Dun Mountain (Geol. Rep. 1870–71, p. 112). A specimen from the Dun Mountain in the collection of the Colonial Museum consists of crystals of a brownish-green colour imbedded in a network of veins of picrosmine.
Hydrous Silicates of Magnesia and Lime.
Meerschaum, 2 Ṁg2 S̈i3 + 3 Ḣ.—The occurrence of this mineral at the Dun Mountain is mentioned (Col. Mus. & Lab. Rep., vi., p. 16), the specimen having been collected by the late Mr. E. H. Davis. "Its colour was pure white, lustre feeble, opaque, structure amorphous; to the touch it has that soft smoothness peculiar to minerals of this class; hardness 2 to 3; easily decomposed by hydrochloric acid. It occurs in contact with massive white quartz, enclosing columnar detached crystals of a dark green colour, probably hypersthene." Its composition is—
| Silica | 53.76 |
| Lime | 2.36 |
| Alumina | 4.35 |
| Iron oxides | traces |
| Magnesia | 20.36 |
| Water of constitution | 19.17 |
| 100.00 |
Dermatin, (Ṁg, Ḟe) S̈i + 2 Ḣ.—This mineral is mentioned by Mr. E. H. Davis (Geol. Rep., 1870–71, p. 112) as occurring in thin faces with smooth polished surfaces at the Dun Mountain.
Talc, Ṁg3 S̈14 + Ḣ.—The occurrence of this mineral is mentioned by Dr. Hector (Jurors' Rep. N.Z. Ex., 1865, p. 438) in quartz from the West Coast Sounds; and again by Mr. D. Macfarlane (Geol. Rep., 1876–77, p. 27) at Jackson's Bay. There are specimens in the collection of the Colonial Museum from Collingwood and Jackson's Bay, both being of a pale green colour. It is somewhat widely distributed on the West Coast of the South Island, being frequently found associated with the crystalline rocks of that district.
Steatite is mentioned by Dr. Hector at Milford Sound (Jurors' Rep. N.Z. Ex., 1865, pp. 266, 437), and it occurs in considerable quantities at Collingwood in a massive form and of a grey pink and green colour; some specimens are foliated. Its position is shown on the geological map of Collingwood published by Dr. Hector (Geol. Rep., 1873–74, p. iv.)